As a matter of fact those are not chain punches as we practice in WT: the main difference is that chain punches are launched while moving forward, and not when you don't (even in demonstrations). The footwork is different, with 100% weight on rear leg and forward step to put weight of the body in motion behind the punches.

A "golden" WT principle is no chain punches from "still" position, but chain punch while moving forward, then when it's no more possible to advance for any reason switch to elbow, knees, chokes , clinch etc.

WT punch is extremely powerful ONLY if you manage to throw it while moving forward, thus putting you weight behind it: an option is to forward press the adversary even with little motion forward, but then you need different foot work than that showed in the clip.

BTW I am not bashing the guy, I am just highlighting differences with what I practice.

I'm kinda spoiled when it comes to seeing some Chain Punches, or something similar to it, but that guy isn't bad. I can count how many he throws so he's not as fast as I've seen it done. I wish the peps I trained with would go ahead and get the seminar pics online, there's a huge guy there, all muscle, who had his arm go limp after a strike from his teacher like those thrown by that Carruthers dude.